Efeitos toxicogenéticos de contaminantes químicos detectados em águas subterrâneas utilizando ensaios in vitro

Abstract

The increase of the anthropic activities provided by the population growth has promoted greater discharge of waste in the environment and consequently the chemical and biological contamination of the water resources. Chemical contaminants at levels above the limits permitted by legislation in groundwater may generate negative impacts on public health, since some compounds have characteristics of bioaccumulation and biomagnification, in addition to their toxic and genotoxic action to exposed organisms. Therefore, this study aimed to: 1) determine metals and emerging contaminants in groundwater; 2) to associate the presence of these contaminants with the land use and cover; 3) evaluate the risk to the population exposed to this water; and 4) to evaluate the effects of cyto-genotoxicity of aluminum and manganese concentrations on CHO and CHO-XRS5 cells. The groundwater was collected in 2015 in the cities of Caarapó and Itaporã in the state of Mato Grosso do Sul. For the evaluation of the water quality, the analysis of the physico-chemical parameters and determination of the metals and emerging contaminants was carried out. Soil use and cover has been evaluated to determine possible sources that influence groundwater contamination. The potential human health risks of the chemical elements identified in this water were calculated by means of the risk assessment. The results indicated aluminum, iron, manganese and nickel with values higher than those permitted by reference legislation and chromium, cobalt, manganese and nickel in concentrations above that considered safe for human health. In addition to metals, emerging contaminants were also identified. Considering the results regarding the concentrations of aluminum and manganese, these were selected for cytogenotoxicity analysis. MTT tests ([3- (4,5-dimethylthiazol-2yl) -2,5-diphenyl tetrazolium bromide], micronucleus and comet assay on CHO and CHO-XRS5 cells were used for these analyzes. When analyzing the cytotoxic and genotoxic effects in these cell lines, it was observed that aluminum and manganese induced significant loss of cell viability and increased genetic damage in exposed cells, even at low concentrations. The results of this study can contribute with data that helps watch agencies to improve the current limits proposed by current legislation and serve as an alert for people who use this water for consumption.